1. Field of Invention
The present invention relates generally to the field of clustering and pattern analysis. More specifically, the present invention is related to the estimation of temporal validity associated with location reports through pattern analysis.
2. Discussion of Prior Art
Location based services and applications are becoming increasingly popular. The utility of a location tracking application is limited by the accuracy of the tracking information entered into the system. While the accuracy of the location tracking reports have greatly increased (particularly since the U.S. government decided to cease the deliberate GPS signal degradation for civilians), the position of a tracked individual at any given point in time can still be inaccurate due to the fact that position reporting modules are not always activated. For instance, a GPS module requires an unobstructed view of the four reference satellites and won't work inside buildings. Location reporting modules mounted inside vehicles only report the position while the vehicle is moving. Positioning modules using land-based navigation through triangulation and radio antennas have a limited area of coverage.
FIG. 1 illustrates the two modes associated with the reception/transmission of location related information. A location tracking application receives position related information via a “pull” 100 or a “push” 202 mode. A brief discussion of each of these modes is given below:                1. PULL: Pulling is performed by the application if the positioning modules can be remotely queried for location information at any point in time. Whenever an application 103 requires location data, queries 104 are performed on-the-fly, wherein the positioning modules 105 provide for the most up-to-date location information 106. However, because of the additional complexity and cost associated with such designs, few systems exist on the market.        2. PUSH: The far most common location reporting technique is to have the positioning modules 105 periodically report their position 108 to the application 103. Several different techniques can be used to report these positions. Some examples include of such techniques include remote method invocation (RMI), Simple Object Access Protocol (SOAP), Transmission Control Protocol (TCP), User Datagram Protocol (UDP) sockets, or email. The downside of “pushing” location data is that location information stored in the application 103 does not represent the real-time position of the tracked entity.        
A problem associated with prior art location tracking systems is that they fail to analyze the history of previous location reports received from a tracked entity, and such systems fail to advantageously use this history to estimate the relevance of future reports over time. This type of analysis is particularly beneficial in the instance that the tracked entity's location is constant over certain intervals of time. Identification of such periods of inactivity is useful in preserving communication bandwidth, since the location tracking system that is aware of these periods of inactivity can stop requesting location information during these periods.
Whatever the precise merits, features and advantages of the above mentioned prior art systems, none of them achieve or fulfills the purposes of the present invention.